In data giovedì 13 novembre 2014 06:39:38, Matthew Knepley ha scritto: > On Thu, Nov 13, 2014 at 6:24 AM, Massimiliano Leoni < > > This is not exactly right because here you are just using additive > fieldsplit. AFAI understood from the user manual, this should be right because my preconditioner is block diagonal, so I want to use block Jacobi.
If I used the other one, P = [[C,O],[B,Mp/nu]] then I would need a multiplicative fieldsplit because this would be lower triangular. Is this correct? > The mass matrix > is a good preconditioner for the Schur complement, not the zero matrix. > Take a look at these slides: What do you mean? I know from theory that the preconditioner I am using is optimal [iteration number independent of grid size]. I read the slides and the manual and the Schur complement is what I was talking about earlier, so it's not what I wanna do now -- even though knowing that it's so easy to implement my be very useful. Anyway, thanks for the slides, they have been enlightening on the power of command line options! > Thanks, > > Matt > Thanks again, Massimiliano
